The electrolytical obtention of layers
Julian Kubisztal, Antoni Budniok Uniwersytet Śląski, Instytut Nauki o Materiałach, ul. Bankowa 12, 40-007 Katowice
Quarterly No. 3, 2005 pages 26-30
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abstract Ni+Mo+SiNi composite coatings were prepared by co-deposition of nickel with molybdenum and silicon powders on a carbon steel substrate (St3S) from a nickel solution in which molybdenum and silicon particles were suspended by stirring. The silicon powder was covered with electroless plated nickel. Ni+Mo+SiNi coatings have been electrodeposited under galvanostatic conditions. For comparison Ni+Mo composite coatings were obtained under analogous current conditions. Chemical composition was determined by X-ray fluorescence spectroscopy method, and quantitative X-ray analysis. It was stated, that chemical composition depends on both the galvanic conditions under which the coatings were obtained and the quantity of powders in the bath. All coatings contain above 10 wt.% SiNi and approx 30 wt.%. of molybdenum (Fig. 2). Surface morphology was investigated by scanning microscope, additionally incision mesh method was applied to evaluate coatings adhesion to the substrate. It was observed that Ni+Mo+SiNi coatings were of good adhesive to the substrate. No internal stresses causing their cracking were observed. Furthermore, these coatings exhibit large development of the surface (Fig. 3). The phase composition, determined by qualitative X-ray analysis of obtained coatings shows, the presence of crystalline Mo or Mo and Si phases built into Ni matrix (Fig. 4). The thickness of the coatings was about 100÷160 μm and depends on their kind, current density, and quantity of powder in the bath (Fig. 5). Key words: nickel, molybdenum, silicon, electrolytic composite layers, galvanostatic deposition